Hi,
First of all, I apologize for the mistakes I could make, my english is not perfect.
I'm an engineering student and I'm getting started with the MSP430 family of MCUs. My goal is to do energy metering using the MSP430AFE253 MCU and to send the collected data via the USART interface in UART mode to a TelosB platform running Contiki OS which is actually using a MSP430F1611 MCU.
My first step in this project was to try sending random data from the AFE253 to the MSP430F1611, a really easy 8bit data exchange . To do so I downloaded the example code packages for both MCUs and wrote a similar code to initialize and communicate.
Here's the code running on the MSP430AFE253 (which is basically the provided example code for UART @115200 baud rate + 2 lines to turn on a LED when the program reaches the interrupt) :
#include "msp430afe253.h"
//******************************************************************************
int isRxIntrPending(){
if (IFG1 & URXIFG0){
IFG1 &= ~URXIFG0;
return 1;
}
return 0;
}
//******************************************************************************
void main(void)
{
volatile unsigned int i;
WDTCTL = WDTPW + WDTHOLD; // Stop WDT
P1SEL |= BIT3+BIT4; // P1.3,1.4 = USART0 TXD/RXD
do
{
IFG1 &= ~OFIFG; // Clear OSCFault flag
for (i = 0x47FF; i > 0; i--); // Time for flag to set
}
while ((IFG1 & OFIFG)); // OSCFault flag still set?
ME1 |= UTXE0 + URXE0; // Enable USART0 TXD/RXD
U0CTL |= CHAR; // 8-bit character
U0TCTL |= SSEL1; // UCLK= SMCLK
U0BR0 = 10; // 1MHz 115200
U0BR1 = 0x00; // 1MHz 115200
U0MCTL = 0x00; // 1MHz 115200 modulation
U0CTL &= ~SWRST; // Initialize USART state machine
IE1 |= URXIE0; // Enable USART0 RX interrupt
P1SEL2 |= BIT0; // Set SMCLK at P1.0
if(isRxIntrPending()){
_BIS_SR(GIE); // General Interrupt Enable set high
IE1 |= BIT6; //Enter RX interrupt
}
}
#pragma vector=USART0RX_VECTOR
__interrupt void USART0_RX (void)
{
P1OUT |= 0x02;
P1DIR |= 0x02;
while (!(IFG1 & UTXIFG0)); // USART0 TX buffer ready?
TXBUF0 = RXBUF0; // RXBUF0 to TXBUF0
}
This code has been uploaded using the FET430UIF debugger and CCSv5.
Here's the code for the MSP430F1611 :
void
uart0_init(void)
{
/* Initalize ports for UART communication. */
U0CTL = CHAR + SWRST; /* SW reset,8-bit transfer, SPI master */
U0TCTL = BIT5; /* BRCLK = SMCLK = 800kHz */
U0BR0 = 0x07; /* set baud rate. 800kHz 115200*/
U0BR1 = 0;
U0MCTL = 0; /* Don't need modulation control. */
P3SEL |= BIT4 + BIT5; /* Select Peripheral functionality for 3.4 and 3.5 */
P3DIR |= BIT4 ; /* Configure TX as output. */
ME1 |= BIT6 + BIT7; /* Enable RX et TX*/
U0CTL &= ~SWRST; /* Remove RESET */
}
/*---------------------------------------------------------------------------*/
PROCESS(uart, "UART process");
AUTOSTART_PROCESSES(&uart);
/*---------------------------------------------------------------------------*/
PROCESS_THREAD(uart, ev, data)
{
PROCESS_BEGIN();
uart0_init();
U0TXBUF = 0x01;
//printf("Process Ending\n");
PROCESS_END();
}
I just try to start a transmission by writing in U0TXBUF. Don't judge me if this seems stupid to you, as I told you i'm a student and still learning :)
The PROCESS_BEGIN and PROCESS_END could be assimilated to a void main() function.
Well, the Contiki part is quite new to me as well. That operating system has been ported to the MSP430 MCUs as far as I know. It seemed to be straight forward since the drivers and librairies were already available so I just wrote the same code I would have written using CCSv5 or IAR.
To sum up, I try to send 0x01 and that turns on the LED I use in the first code which means I receive something. Well the value I receive changes everytime I run the code. Besides, when I echo what I received I check on the RXBUF of the MSP430F1611 and all i get is 0x40. That makes no sense to me and I can't figure out what's wrong.
I don't know yet if the problem comes from the code itself or from the the fact I'm trying to run it using Contiki.
All your tips, advices and ideas are welcome ! :)
Thanks a lot,
T.HOROZIAN
